


Achilles Heel

by MrsTomMarvoloRiddle



Category: Harry Potter - J. K. Rowling
Genre: F/M
Language: English
Status: Completed
Published: 2017-06-15
Updated: 2017-06-15
Packaged: 2018-11-14 07:02:01
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,270
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11202876
Author URL: https://archiveofourown.org/users/MrsTomMarvoloRiddle/pseuds/MrsTomMarvoloRiddle
Summary: They were each others one weakness, she was his sirens call, he was a challenge and game that turned into something more. Bellatrix Lestrange and James Potter were tied together.





	Achilles Heel

James knew that what he was doing was completely and utterly wrong, but he couldn't bring himself to stop. Just like the magic she practiced, she was addictive. And James didn't have enough will power to stop, at least that's what he thought, he didn't want to think that there was another reason that he kept going back to her.  
~O~  
Her hair was wilder than his, curls were everywhere. Her heavy lidded eyes constantly held a mischievous look, but it darker than the one James’ eyes held, like she was always in on a joke that would cause harm to whoever she was talking to. James was simultaneously terrified and in love with the look.  
~O~  
Bellatrix Lestrange was James Potter’s weakness. When he finally got the girl he pinned for for years, he planned to end it, but when he went to tell to tell her, he saw that look and her smirk. Her longed black dress hugged her body and her voice was dark and alluring. All of that combined made him forget all of his reasons to put a stop to their meetings and he pulled her flush against his body, slammed his lips to her in an angry and violent passion filled kiss. She always brought that out of him and the more time that passes, the less he can bring himself to care.  
~O~  
He is still with Lily, he finally got the girl and he wasn't about to give that up. But he also couldn't give up Bella. He’s always been told he was selfish. James and Bellatrix were so different in everything they did and believed in, so their reunions were always explosive. Plus, even if he wanted to leave Lily (which he didn’t), Bellatrix was already married. They wouldn't have it any other way, their secret kept them alive.  
~O~  
Lily was pregnant, James was ecstatic and Bellatrix couldn't care less. His meetings with her were less frequent, but they still happened. They even met and came together during a battle between the Order and the Death Eaters. The place and time made it all the more dangerous. It was the most explosive out of all of their get togethers.  
~O~  
James had a son named Harry James Potter. James and Bellatrix were never up for talking, it usually led to a fight which became physical, both intimately and violently. They usually never have enough time for that. Though, he still tells her about his son and he's prepared for a comment on his filthy mudblood of a wife and halfblood of a son. So its a surprise when she just asks if he would prefer a son or daughter for his second child. He’s confused about why she asked, but he answers her anyways. He always wanted one of each, She looks him in the eye as she outs her arms around his neck and says, “Well lets hope I give birth to a girl then.” He stays there frozen as she laughs and apparates away. James never expected, nor did he want, this to happen.  
~O~  
James could only think about what Bellatrix had told him. A child, not one of his and Lily’s but his and Bella’s. It was the first time he felt any sort of guilt about what he was doing. But it wasn't guilt about what he was doing to Lily or his son, but to the child that he could never be there for.  
~O~  
James went into hiding, but he still met Bellatrix. It happens in the dead of night when his family was deep in their sleeping. While he was gentler with her than normally, it was still all teeth and nails; he was positive that they'd both have bruises in the morning. But that was they way they liked it, so different from anything in their day to day lives.  
~O~  
It was March when he thought Bellatrix didn't show for one of their planned meetings. It wasn't uncommon that they had to reschedule, but neither of them never not showed up without informing the other why. It made him nervous. James didn't know what could possibly be holding her from coming to him tonight. He was about to leave when he heard a small pop and her voice. James turned around and there was the women on his mind, only she wasn’t alone. In her arms was a baby, but not just any baby, but his child. She didn't seem sorry for being late, but said it took longer than expected. He froze for a second before he quickly snapped out of it before working his way towards the women he shouldn't have been with, yet together they created life. 

He stepped in front of Bellatrix and looked down at their child. There was a small amount of pure black hair that was already starting to curl like Bella’s. When he asked whether it was a boy or girl, Bella responded with, “You got your wish of one son and daughter. Her names Cassiopeia Dorea Lestrange.” 

James looked at her and said, “I thought you going to give her the last name Black.” he tried not to sound angry.

Bellatrix just rolled her eyes and replied snidely, “And if your precious wife asked you to give little Harry the last name Evans, what would you do?” 

James just stayed silent, and continued looking at his daughter who finally opened her eyes. They were a mix of his and Bella’s, they were mostly grey but had touches of brown and green to show her father’s hazel eyes.  
~O~  
There were times that their meeting had their daughter, but they met up plenty of time without her so that they were free to be as fierce and violent as they usually were before Bellatrix was pregnant. James always had to do a little first-aid when he got home before he checked on Harry and climbed into bed with his wife.  
~O~  
Sirius comes for a visit and drops a bombshell. Well, Sirius thought it was a bombshell and for Lily it was, but James already knew. Bellatrix Lestrange had a child. Sirius didn't know much more than that as he only saw her with a baby, he wasn't able to tell them the gender or name. Sirius gave Harry his birthday gift and left, but not before noticing James called Bellatrix’s child a “she”.  
~O~  
James pushed himself up and off of Bella before laying next to her. Panting, he was about to get up to get ready to leave before he was suddenly yanked down. On top of Bellatrix once again, he laughed and gave in to her. After two more rounds that she got out of him, he looked over and asked her why she was so energetic this time. Since Cassiopeia (Bella hated when he didn't say the full name) she had been more tired than usual. Tonight though, she was back to her lust filled energetic self. 

She merely replied, “Its Halloween James, theres something in the air.” He just laughed, kissed her and got up to put his clothes back on. 

Before he disapperated he heard Bella say, “I’m sorry” he turned back but there was a pop and she was gone. James shook his head and appeared to his wife and child. Little did he realize what awaited him at home.  
~O~  
His wife was dead and his son was a savior. He realized why Bellatrix apologized, she kept him from his home. He was both incredibly angry and extremely grateful. Angry that she kept him from trying to save the love of his wife, but grateful that he knew that if he was there he wouldn't have survived and he was still here to keep Harry safe. He realized that that she went against their pack to not involve the war so as to not help or harm their sides. Bellatrix Lestrange always surprised him.  
~O~  
He ignored Bellatrix for a month. He was able to ignore her until he read the Daily Prophet and saw that Bellatrix Lestrange was expecting another child. That night he left Harry with the House Elf to meet with the women who he has refused to see. 

When he she came, he just looked at her and asked, “Is it mine?” 

Bellatrix just scoffed and replied, “The only times I have ever had sex with Rudolphus’ was on our wedding night and three times when I realize I’m pregnant.” James smiled and hugged her, but he was still bitter, this should have been his and Lily’s child. He didn't apologize for ignoring her and she didn't expect him to.  
~O~  
He asked her why she did it one night after they finished. She just smiled and replied that he'd have to be more specific. He rolled his eyes and said Halloween. She turned to him and looked into his eyes, not saying anything. James was getting nervous the longer she stayed silent. 

She finally spoke, “Spite.” She didn't elaborate until he broke down and asked her. 

She laughed and told him, “He wanted her, but he also wanted all the Potter’s. I couldn't let him have to and my star. And now, He can’t have either of you.” She gave him a soft kiss and got up and apperated before he could even digest what she just said to him.  
~O~  
While James dearly missed his Lilyflower, he couldn't deny it was immensely easier for Bellatrix to come to his house, though now he lived at Potter Manor (he couldn't live where Lily died and his son almost murdered). It was also nice when she bought Cassiopeia to play with Harry. He wasn't sure how much longer they would be able to play together though. James just enjoyed it for now, not wanting to think of the future. The children playing together gave the situation a sense of normalcy and because of that, they were a bit colder more so than normally.  
~O~  
Two weeks before Harry’s second birthday, Bellatrix came over with his third and fourth child. Two sons named Regulus Charles Lestrange and Hydra Cygnus Black. 

He smiled wryly and asked, “You couldn't have given them normal names?” 

“I would have thought you would like that Regulus has your middle name. Rod wanted him to have his name you know?” Bellatrix quipped.

James looked affronted at that. He would make it his mission to destroy her husband. It was bad enough that two of his children had to have his last name.  
~O~  
They were almost caught once. By Sirius. The children were in the playroom being watched over by a Potter and Estrange House Elf. Harry was approaching five and soon his children wouldn't be able to come over anymore, in fear that they'll let something slip in their childhood innocence. 

James and Bella were in the throws when they heard footsteps and a voice, “Oi, Prongs! Where the bloody hell are you?”

They froze for a second before springing into action. Bellatrix sprang up and cast a disillusionment charm on herself. James waved his wand to straighten the bed sheets while throwing on his clothes. He also told Pinky to lock the play room, in case Sirius went there. That fear was unfounded because as soon as James put his shoes on, Sirius came through the door. Without knocking. James went to hug him and to guide him out of the room. He saw Bella’s clothes on the floor and just hoped that Sirius didn't see the pile. 

Thankfully, while guiding Sirius to the lounge he felt Bella and the kids go through the floor. While he was glad that she left before Sirius could catch them, he was left very unsatisfied and immensely tight.  
~O~  
Harry was going to Hogwarts and James couldn't believe how fast time was flying by. He just got back from the platform and Bella was at his home to comfort his empty nest. At least that what James liked to think, he never really knew what was going through that twisted mind of hers. She was there before him, she's had been keyed into the wards for years now. They had fell into bed and spent the next few hours there. At two, James asked when she had to leave, she just said the kids were at her sisters, and who gave a damn what Roddy thought. It was all he needed to get back on top of her again. 

It was late into the night and he and Bella were eating in his bed when Harry’s owl Hedwig tapped on the window. James got his wand to open the window.

As Hedwig flew over, he exclaimed quite excitedly, “He must be telling me how Gryffindor is!” 

Bellatrix just rolled her eyes and said, “Well, is he started into the House of the stupid and reckless?” When she got no response she turned to face him. Bellatrix could help her laugh at the expression he wore. She took the letter out of her hands to see what made him look so dopey. 

Reading it, Bella’s eyes got her trademark mischievous look in them and she let out a belly laugh, “Slytherin?” 

James looked up at her, “How did this happen? Oh Merlin, Sirius is going to throw a fit!” he wailed, falling back onto the bed.

“Maybe he is my son and not your precious Lily’s. He obviously doesn't take after that filth.” Bellatrix said flippantly, still looking at the letter. 

James glared at her coldly and grabbed her arms in one of his and put them above her head.”Never say something like that again. Otherwise I will wringe your neck and not the way you enjoy it.” 

Bellatrix didn't comment on the treat, but instead asked, “Did you finish the letter?”  
James looked slightly sheepish and replied with a no. 

“Well it looks like he's made a friend.” 

James looked up, “Really? Who?” “

Oh. Just my nephew, Draco Malfoy.” She used is shock to get out his hold and push him onto his back. 

“Don’t make threats you know you wont keep.” She got up and left, it was time to pick up her children.  
~O~  
James’ life was good. He had a great job, a son at Hogwarts, and three beautiful children. He did admit that it was unfortunate he couldn't claim them as his, but he knew the truth and that what mattered to him. Bellatrix, the mother of those three children. He knew how wrong it was for them to be together. They were on opposite side of the war, and even though the war ended the night his wife died, they definitely still held onto to their own beliefs. He didn't love her, but he kew that he he cared for her on some level. 

James Potter didn't know how his life ended up like this, and he wasn't sure if he would want to change it. At least, James thinks, that he’ll never has to face that question.  
~O~  
Bellatrix floo’d that night just like they agreed. They were waiting for Cassiopeia’s letter to see what House she’d been sorted into. When James heard the floor, he ran and immediately asked if she read it.  
Bellatrix laughed at him, he knew how impatient she was, “You really shouldn't ask stupid questions. Of course I’ve read the letter.” Instead of starting a verbal sparing match, James just snatched the letter out of her hand and read it for himself. As he read, Bellatrix waited and watched, ready to see his reaction. 

“Slytherin? Are you fucking kidding me? Of course you bloody snake shave turned my daughter against me.”

Bella smirked, “You a Gryffindor, raised a Slytherin.” James glared and she laughed, taking his hand and leading him up the stairs.  
~O~  
Bellatrix walked into his shower. He wouldn't have minded, but he didn't even know that she was coming over. He will go to the grave saying that the girlish shriek was the pipes and not him when he felt her hands. Before he could talk to her, she captured his lips with hers and wound her fingers in his hair. He gave in. He finally asked her why she came over as she was about to leave. She looked at him with a blank expression that made him nervous. 

“Your going to be a dad.” Bella told him with her trademark smirk. She then floo’d away. James just thought that they needed to be more strict on their protective charms.  
~O~  
It was rare for them to relax in bed. neither of them particularly enjoyed cuddling. They never liked being that vulnerable, but that night was different. They were lounging on James’ bed enjoying the silence. 

James turned his head to look at Bellatrix, “I want to talk about the baby’s name.” he told her. She glanced over at him with a look that told him to continue. 

“I don't want them to be named after the Black tradition.” 

“Excuse me? This is the first time you've wanted an input.” The glare that he got almost made him back down, but he kept going. 

“I know, but Cassiopeia, Regulus and Hydra already are names after it. I want them to be named differently.” 

“Fine, no stars or constellations.” James was proud that he one that one.  
~O~  
James was working when he got an owl in his office, he grabbed the letter of the leg and read: “Your fifth child has been born. Im at your house for the next hour.” 

James didn't even tell anyone he was leaving. When he got back, he was greeted by the sight of Bellatrix ordering his House Elf to get her tea. She had a cradle in front of her. He came up to it and saw a sleeping baby with tufts of blond hair. 

“She has my mother’s hair.” he heard. 

“What’s her name? Wait, let me guess. Amanda? Susan? Rose?” James stopped when he saw that Bellatrix was getting more and more agitated with him. 

“For the love of Merlin her name is Narcissa Iolanthe Black.” Bellatrix snapped setting her tea down. 

James just stared and said “I thought we agreed-“  
“I agreed no stars and constellations.” she said cutting him off, “You never said that I couldn't give her that name.” Bellatrix calmly continued. 

“Plus, Cissy deserves it. She loves them and helps out a lot. Plus she has a Potter middle name like Cassiopeia and Regulus.” James knew that he lost. 

“Bloody snakes and the loop holes.” he muttered. Bellatrix laughed and smiled down at her daughter who inherited her grey eyes.  
~O~  
That September first of 1993, Bellatrix refused to come to his Manor. Instead, he makes the Floo trip to Lestrange Manor. While James didn't exactly want to go, he was excited to see where four of his children lived. He saw each of their rooms.

Cassiopeia’s was decked out in silver with green accents and the Lestrange and Black family crests over her bed. Regulus’ was mostly grey, but he smiled at the dark red walls. It was Hydra’s room that surprised him. It was white except for the dark floors and black wood furniture. He loved the small insight he was able to get into his children by looking at their rooms. James did derive an immense amount of pleasure fucking Bellatrix on Rodulphus’ bed. Before their second round, they heard the tapping of an owl. With a wave of her wand the window opened and the owl flew in, a letter on each leg. They opened Hydra’s first.  
“Ravenclaw? Are you serious? Thats a surprise.” Bellatrix commented a little bitter. 

James sighed, “Im just glad that he isn't in Slytherin. Though now he doesn't have anyone to protect him.” 

Bellatrix slapped me and sneered, “My children are well enough to protect themselves.” 

James rolled his eyes not thinking that its worth the fight. Regulus’ letter was next. Both James and Bellatrix couldn't believe that one of their kids ended up in Hufflepuff.  
~O~  
Harry was entered into the Triwizard Tournament and James was scared. He didn't know what happened or why his son was put into an extremely dangerous tournament. He put it down to the title the wizarding world gave him: The Boy-Who-Lived. He always hated how much pressure the world tried to put on Harry, but he refused to give them what they wanted. He raised Harry to be nice, humble, and maybe slightly mischievous. 

He was worried that a Death Eater was somehow able to get Harry’s name into the the cup. So he went to the only Death Eater he could trust with his son. He wasn't nice, he was rough and let all his anger out on her about the situation. She let him. When he let all his anger out on her she told him she didn't know anything, only that everyones Dark Marks were returning to the black it once was instead of the fade dull grey it was. He believed her.  
~O~  
Voldemort has returned and everything has gone to shit, at least in James’ opinion. His eldest was taking a lot of heat from the press. He hadn't had a chance to meet Bella, but she was able to give him a letter why.  
Our house is home, the children are safe  
but our star has met someone new.  
James was terrified, but he knew Bella would protect them and the rest of them.  
~O~  
Bellatrix Lestrange was his most loyal. She did everything he asked and she did it to the tee. She was his right hand. He trusted her more than the others. Then He learned that she had three more children when he was gone. He told her that he was proud she was raising the future generation. Doing her duty to her family more than anyone else. She know that was a dig against her sister, but she wouldn’t, couldn’t, let it get to her. In his first month of being back of she was tasked with killing Amelia Bones which she did gladly. She was dedicated to the cause. 

James didn't hinder that, she ignores the thought of her making him stay on Halloween so the Dark Lord wouldn't kill him. He frequented her Manor, she didn't mind. In fact, she was extremely proud. That is, she was until he saw her oldest for the first time in thirteen years. At fourteen, Cassiopeia has grown beautifully. She had her mother beauty and grace. The look the Dark Lord gave her pause, but the look her daughter gave him made her stop. Cassiopeia was more like her mother than James knew. She was attracted to power, and the Dark Lord was pure power. Bellatrix knew James was going to kill her when he found out. 

~O~  
While the Dark Lord kept silent Harry’s fifth year, the summer before sixth year he kicked into action. James was never busier. Between being an Auror, an Order member, a father, and a lover of an enemy. He barley had a minute. He didn't mind though, everything he was doing, he enjoyed.  
~O~  
Their relationship was like it was fifteen years ago.. A very strict line was between them; separating their sides. Their guards were drawn up again. They talked less and they were rougher, more painful. They did miss one aspect of that time, no matter how how twisted. Fucking on the battlefield was exhilarating. They both agreed that there was nothing like it. 

~O~  
Dumbledore was dead and Bellatrix was outed. James didn't know what was going to happen. She was on the top of the most wanted list. He was assigned to capture her dead or alive. He was glad that he left the job when he was home, otherwise he would be in a sticky situation (more than he already was). His children were living in Malfoy Manor. He wasn't sure whether Bella was living there because of the predicament it would put her family in, but Lestrange Manor was on constant watch (the Aurors couldn't get into the wards- and for that James was immensely relieved.  
~O~  
Bellatrix and James were upset. Bellatrix because James wouldn't tell her why Harry wasn't attending his seventh year. James couldn't tell her that Harry and Sirius were hunting her precious Lords horcrux’s. James was upset that Bella wouldn't tell him why Cassiopeia wasn't at Hogwarts for her sixth year. Bellatrix didn't think that he would want to hear that his daughter was pregnant with the Dark Lords child.  
“Just tell me that she isn't a Death Eater. That I don't have to worry that i'm going to see her during a battle.” James pleaded with her.

Bellatrix, ever the Slytherin, told him, “Don't worry James, she wont be fighting.”

Only after she left did James realize that Bellatrix didn't answer the first part of the question. 

~O~

Bellatrix and Narcissa were the only family members of Cassiopeia’s allowed in the room while she gave birth. The Dark Lord wasn't there, but in the room that he claimed as his study with Lucius and the Lestrange brothers.

After hours of labor her little star gave birth to a baby girl, Delphini- Delphi- Bellatrix Merope Riddle. Bellatrix knew it was time to tell James. Unfortunately for her, the next day was May 2nd 1998.

~O~

James got a message from his son and best friend letting him know that they were at Hogwarts. James had a feeling it was time. Voldemort and his followers arrived once it was shown to Snivellus that the Order had infiltrated Hogwarts. He fought with all he had. He saw Bella fighting with Hestia and they made eye contact. This is one battle that they could not sneak out of. 

There was a pause in battle. Tonks was dead, killed by her own aunt. James knew that that she had wanted revenge against Andromeda leaving for a long time. Remus was dead to. There were so many other dead, but James was only glad that his children were alive. 

Harry didn't tell him what he was going to do. James knew it was because he didn't want to be stopped. James couldn't be happier when he saw that his son was alive when Voldemort came to gloat. Once Harry started running, James followed him immediately. Once he knew that Harry was okay and what his plan was, James felt secure enough to find Bellatrix. He needed to talk to her. 

He found her between fights and before anyone could notice he pushed her into a closet. A kiss was shared and then he asked the big question, “How are the children?”

“Cissy is fine, she's at Malfoy Manor with Cassiopeia. Regulus and Hydra have been taken there by my sister and her family. The Dark Lord doesn't know.”

James sagged with relief. One of his children was in danger he couldn't risk another. James was about to leave when he was stopped. James turned around curious as to why she held him back. 

“There is something that I need to tell you about our daughter.” Bellatrix told him. James was worried, only something big would put that look on her face. 

“Cassiopeia missed her sixth year because she was pregnant. She gave birth yesterday.” James stopped breathing. His little girl had a child. 

“Who? Who it the father?” James spitted out. 

Bellatrix, fearless as ever looked straight into his eyes and said, “This isn't what I wanted. I hate him for it, but I couldn't stop it. The Dark Lord is your granddaughters father.” She left right after saying it. 

James felt a rage he only felt once before. He was vicious, cutting down Death Eaters left and right. He was back in the Great Hall when he heard Bellatrix’s trademark cackle and Molly Weasley yelling something about her daughter. He ran to the fight instinctively. He got there in time to hear Molly yell the death curse. Before it reached Bella, he pulled her to him saving her life.

The Weasley’s were in shock. James ignored them and kissed Bella pouring his anger into it. When he released her, he said, “I’m the only one who should be allowed to kill you, plus our children need their mother.” Bella laughed and rolled her eyes.

“Only a Gryffindor would be stupid enough to announce a twenty year old secret in front of hundreds of people.” James’ expression turned from hard to sheepish.

“Well, we cant have this getting out can we?” he said.

Together they turned toward the gapping Weasley’s, who were the only was paying attention to the scene, and together pointed their wands and said “Obliviate”. 

~O~

11 Years Later  
Cassiopeia was in the platform 9 3/4. She was dropping off her younger sister and daughter. Cassiopeia always felt bad on September 1st because her sister was the only one of them to not be out on the train by their mother. Though it wasn't like Narcissa didn't have a big goodbye with their mom. Bellatrix had been in hiding since May 2nd 1998. Though she was living at Potter Manor. 

Cassiopeia still couldn't fully believe that her mother had been shagging the father of the Boy-Who-Lived. Cassiopeia was broken out of her musings when her husband Draco Malfoy came up to her with their daughter. Her family did quite a bit of quick thinking when the Dark Lord was defeated. She had to protect Delphi and marrying Draco was the way to do it. They had Delphi and three year old Scorpius. 

“Peia, where’s your sister?” he asked, wrapping his arm around her waist.

“She is already on the train. She wanted to make sure to get a good seat on the Prefect cart. I can’t believe she’s a sixth year.” Cassiopeia replied, looking her daughter over as Delphi said goodbye to her brother.

Draco hummed in agreement, “I remember when she was born. Mother was so excited to find out she was named after her. I find it funny how your mother loved to put answers under our noses. I mean, three out of the four of you have Potter middle names.” 

“Dearest husband could you be any louder?” Cassiopeia said, “Though you aren't wrong. Mother did have a twisted sense of humor.”

They stopped talking to make sure that Delphi Malfoy got on the train okay. As they walked to the apparition point Draco asked, “Is Regulus coming to dinner tonight?”

“He is, though unfortunately he is bringing that chit of a fiancé. At least Hydra married well.”

Draco rolled his eyes, “Gabrielle is just as good as Daphne.”

Cassiopeia side eyed her husband, “She’s part veela! Plus her older sister is married to a Weasley. The family that tried to kill our Mother.”

“ You realize that Harry almost married a Weasley right?” Draco said, trying to stop the laughter that wanted to come up. 

“Please, once he found out Daddy dearest’s secret, he knew he couldn't marry Jenny.”

“Its Ginny.”

“Whatever. Luna may be weird, but she is sweet and malleable.” Cassiopeia said, holding Scorpius tighter as they got closer to the apparition point. 

“No wonder you’re Aunties favorite.” 

Cassiopeia lifted her head, face taking on a haughty look, “Of course I am.”

“Let’s just go home, we need to make sure everything is in order for tonights dinner. And I can do without a fight on the platform erupting due to someone hearing us.”


End file.
